Mold



June 23, 1925. 1,543,657

' c. B. BOHN ET AL MOLD Filed Nov. 20, 1922 9 Sheets-Sheet 1 l// 2 X l fici. 2.

I wi/ewmeaz' 14M June 23, 1925.

c. B. BOHN ET AL MOLD Filed Nov. 20 1922 9 Sheets-Sheet v2 l||| .lll||| Illllllll Ilxl I. III llillllllllllll III Army June 23, 1925.

C. B. BOHN ET AL MOLD 9 Sheets-Sheet 4 Filed Nov. 20, 1922 3 F w m a WM H E w AWVV c. B. BOHN ET AL MOLD Filed Nov. 20, 1922 9 Sheets-Sheet, 6.

June 23,1925- 1,543,657

c. B. BOHN ET AL mom:

Filed Nov. 20, 1922 9 Shets-Sheet v Anw fx,

'June' 23, 1925.

c. a. BOHN ET AL HOLD Filed Nov. 20. 1922 9 Sheets-Sheet 8 pi-oclu'ceziluminum "alloy Patented June 23, 1925 CHARLES B. 1:01am Alib Dm'mmm eFrnmwmww ii fiifi MESNE ASSIGNKEN'ES, 7T0: MEN-xlgfiMINBM-E BRASS eogrom'non, 015" mi'nnmm,

MIGHIGANfA eoiironmmoner lawman.

' The inve tion su'eh alumin um; mid mag iesiiiin Kind &5- peeiallybyl'inder Head cast ng *foi'fii terfiaI coinbiistion e gines ":fncl othei' ejs'tiiigs of a siniila hiu actei'. M

"He-Tetofor'e it has been" ouiid low melting Iioirit of these meme-and I rehitiifelylow te npefzitiiie 'et xi hio h the are poured, "in comparison iron or steel castings. A W I tel i'per'aitiii'e 'of I the 'light wifeight Iiital "E lmuch quicker than cl'e iron oiijst'eel "eastmolten metal is iii uc h, le s s likely' to e agpe. The 'sliiiink zig'e eraeks; aiicl 1 ch-ewe, "e o iii 'e largely explained by the i'elpid fi'ezihgflbf th'e light-weight "alloys although their high crystallization shrinkage isiilsofa f iqltbi'. If the casting has 'jSQIHfSlCtlOIiS' thlpiil than others," these thin Seotions,:'ff ee zii1g Anotherobject of t'heinx'viitio'ii 1 3m 1516 I "Anbthf-objet of the iiiviition isto pio vid'e' iih irhiiibv'ecl gzitiii'g" fer molds (ifthe character in quest ion.

"-Fiiithr bbj'ects of the iiij eiition "moi'e or less ancillary to the foregoing iiiill ajjpfelir in the "fdll'owihgfile'oiifitioii' in which is "Set forth in conpeetion ith the accompanying u'i'kagemraoks' and draws in subh- Q-Ewe production of c'a'stiii'g s, v

In thedrawings, F ig, 1 is a. plan view of tlie ihcil'd' o'ii a'iedil'otl some.

Fig. 2 is 3- side elevation of the same.

Fig. "3 "is 'a plain view (5m l'afger 'scz'il'e of the mold drag. A ,7

Fig. 4 1m Bbttoih lain View 'onthe same scale of themold cope. g A ---Figb 5' is a *etion ""the broliei fli-ne V V, Fig. 1, but on thesame scale asFiQs. 3a-nd 4mm Section heiiigindie'sitecl' in certain of theother figures by the 'lii'1e{55.

ig. '6' is 'a siihi-l2i 1ly-enlarged section on the broken line VIVI, Fig.1, the loc'atio'n of the "section be'iiig 'ihdie'atedon certain "of theother figures by the 'liIie"6 6 7' is 'a" fifigriieiitary "section on the line VII-VILFig. 6. v "Fig. 8*is' affi'a 'i iitery section on the line.VII 111,i igys. F 1

Figi is in enlarged sje ctiononthe broken line IX'IX, Fig. 1, the location of the section being indicated on certain of the other figures by the line 9-9.

"Fig; 10 is an enlarged section on the broken line X'X, Fig. 1, the location of the section being indicated on certain of the other figures by the line 1010.

Fig. 11 is an enlarged section on the broken line XIXI, Fig. 1, the location of the section being indicated on certain of the other figures by the line 11.11. v Fig. 12 is an enlarged section on the brokenline XII XII, Fig. 1,- the location of the section in certain vof the other fig ures being indicated by the line .1212.

. Fig. 13 is an enlarged section on the line XIIIXIII, Fig. 1, the location of the section being indicated in certain of the other-figures by the line 1313. V

Fig-14 is an enlarged section on the line XIV-XIV,IFig. 1, the location of the sec- I tion being indicated in certain of the other figures by the line 14 --14.

Fig. 15 is a fragmentary section on the broken line XVXV, Fig. 3, the location of the section being indicated in certain of the other figures by the line 15 -15.

i Fig. 18 is a side elevation of the casting shown in Fig. 17.

. Fig. 19 is an end elevation ofthe casting shown in Fig. 17. i j

Fig. 20 is a plan view of the machinefinished casting.

Fig. 21 is a bottom plan view of said finished casting. t

Fig. 22 is an end elevation of the casting. 7 Fig. 23 is a section on the line 1 1a14,

Fig. 20.

Fig. 24 is a section on the line 13-13, Fig. 20.

Fig. 25 is a section on the line 1212, Fig. 20.

Fig. 26 is a section on'the broken line 11-11, Fig. 20.

Fig. 27 is a fragmentary section on'the line 1515, Fig. 20.

Fig. 28 is a fragmentary section on" the line l616, Fig. 20.

Fig. 29 is a side elevation of the finished cylinder head.

Fig. 30 is a section on the broken lines 9-9 in Figs. 20, 21 and 2326.

Fig. 31 is a section on the broken. lines 66, Figs. 20, 21 and 23-26.

32 is a view partly in side elevation and partly in section, the section being taken on the broken line 55, Figs. 20, 21 and 2326. 7 V a Inasmuch as the significance of our improved mold construction is especially related to the character of the casting produced by it, reference will first be had to .the casting itself as shown in Fig. 17 to 32, inclusive. Referring to the finished cylinder head as shown in Figs. 20 to 32, inclusive, it will be-observed that the head comprises a main wall a, a water-jacket wall I) and walls 0 forming a branching fuel intake passage with an inlet d and three outlets at e, f-and' g." The head is intended for use on a six-cylinder sidevalve engine and the three outlets e, f and g are designed to register each with a passage in the cylinder casting, which latter passage divides, with onebranch leading to the valveecontrolledv inlet of one cylinder. and the other branch leading to the valvecontrolled inlet of a second, adjacent cylinder. The main head wall a and the acket wall 6 are connected by a plurality of through-bolt bosses h, h.

.The inner side of the cylinder head has a plain flat surface except for the six recesses awhich are formed to accommodate the lift of the inlet and exhaust valves of the six cylinders. The wall a is formed with six spark plug openings a and at one end of the head, the jacket wall 6 is formed witha water outlet opening I). The cooling water finds its way into the jacket space through various openings, 6 b in the wall a which communicate with the water jacket space in the cylinder casting.

As has been-indicated above, Figs. 20 to 32, inclusive,.show the cylinder head in its finished state resulting from the machining of the casting. It is unnecessary to refer to all. of the various machine finishing operations but two of them should be mentioned because of their relation to the production of the casting. The various through-bolt bosses of the head as a practical matter must be cast solid and then drilled out to receive the bolts. The result is that the casting has some relatively thin sections and some very heavy sections, and the thin sections merge more or less abruptly into the heavy sections. Thus the waterjacket walls 6 are thin while the bolt boss sections are exceedingly heavy. In fact the main wall a of the head casting is substantially heavier than the jacket wall b and in a number of instances, as shown for example in Figs. 23 and 24, it is practically impossible to avoid extra masses of metal where the wall a, the bolt bosses h, h and the fuel passage walls 0 merge.

The second machine-finishing operation referred to, is that of the inner side- 0f the casting. It-Willb'e observed that this inner side of the cylinder head has a plain. flat surf-ace throughoutiex'cept for the recesses a. Obviously the fiat portions of 'this'sub. face are susceptible ,ofinachine finishing by a simple operation.- "The mannerin which the iecesses a are provided with a smooth finish will be referred to below in the. de; scription of themo'ldg- I Turning now. to the mold asiillust-ratedin Figs. 1' to16, inclusive; it eomprisesia drag 1 and a cope 2 Which are enclosed'lin the lower and upper -sections 3 and 4 of a suitable two-part fiask. sThe' -inoldrests upon a suitable board or base 5. Preferably the two sections of 'the flask are forined of; metal castings having their'abutting edges accurately machined so that theyfit nicely togetherf The base 5'is also preferably in t'heform'of'metal casting-With its flat top surface smoothly finished. The =fiask sec tions are formed with the usual ears or lugs 3 3- 4? to be enga ed'by clamps- 6 thatjserve to hold the flask} section's securely together while the castingbeingpoure'chg which is shown in plan in Fig. 3'a1id'i1i"section in Figs. 5'; 6; '9 and -11 tol is prefer-ably forined of ordinary green molding "sand. Siibstantially the entire mold or casting cavity is formed in the drag, the arr-angeinent'being such that the topof the" cylinder head is down while the bottom of said casting, which forms the inner 's-iirfae of; the cylinder head; is up and substantially;- level with the top surface of; the drag; In -the drag is placed a baked sand;core27 -Which forms the'water jacket cham'b er ofth'e casting. This'co're is formed at one end witha cylindrical extension 7* and at its ether-end i vi th a heavier oval extension 7 which en"- gage recesses'i-n the drag seas-to support the core (see Figs.-3,' 6; 7 and Overthec'ore extensions/( and 7 are placed baked blocks 8 and 9 which are recessed "to lit the extensions and ill-ave their top surfaces in line with the top sur'fa'ce of the drag." The core 7 is also defined 'on'itsfunder side with two bosses 7, 7 which engageirecesses in small 'nietal chills -10 e1nloedded'-in --tlie green sand of the drag, thus furnishing-additional sup-port for "the-core; Thefholes formed by these bosses in the wall 6 of the casting can be closedwith plugs.

The Cops 2 is roamed "ofbald sand. The main body of the cope can be'rnade oford-inary'core sand but ive preferto provide it with a facing 'Q of specially fine core sand. In piacti'ce We 'n'iakethe facing sand rnjixtn re ivith't'he renewing composition:

' 1 2 bu'ckets' 1 5 quarts cap city) 1 Mich-i- 'The mainbodyofth'e d theehreugh belt'bosses of the'castimg. the" mold c'avity' pi' oper i-cornprises Iaibotitom :The backing sand mixture is Inadeup with the;followingcomposition: .7 buckets old. (bu-int) sar (1, 4 buckets Michigan City sand; 4 buckets, bank sand, 4 quarts rosin; tqnarts piteh. v- I To the inneiu-side' of the. cope-is pasted a baked:sandcore-1l-which for-ms the cha na ber of the. fuel intakepass'age of the cylinderhead, As is shown in Figs. and 5,;the core Y 11' is, formed,- With three tapered extensions 11 and also With a cylindrical BXtQIlSlOBfll which engage suitable recesses ini the cope.

i The; cepe2 has, embedded in it a series of sixprojecting metal chills 12; 12 which are designedto form the; recesses ja ofthecylim d'erfca'sting previously referred to. ,E; h chillhas formed onits bfickjsnrface a loop or eye .vihich serve'sto efiectively ock it in the sand and also serves as; a convenient handle by "which. the; chills can zbepicked upwith a hook when the hot-mold is broken up; 7 some of the; larger Watercircnlating open, ings b of the cylinder head. The cope 2 is formed with a pluralityeof risers'lg; 14 which extend upward .frem-the-mold cavity proper in a manner and for purposes which will presently be explained. Y

The moldis provided .Wlth-EWQ gates,idesignate'd in their entiietiefi'by l3, l3 (see'Fi'gs. .10, :12zand 14); and formfidapfirtly in. the copeuand partly in thefiragiwEiwh gate comprises a; sprue 13 with a. L 'Bd opening to receive themolten'metitl from the ouringladle. 'Thesprue leads'intonone r end of horizontally extending skim ehja ns ber 13 of large capacity. .Withthe. other end of this chamber a riserl?) coimnuni cates said riser like the sprue l3 'having' a flared top. The. skim chamber 13; ovrlie'fi a shallow depression 13 in. the top of the drag and this depressionv communicat s by means of a series of shallow restrictedin gates 13 with the adjacent" side ofthe mold 'c'avity-atthe top thereof. Y 1 I Referring to the various longitudinal and transvere sectional views of the assembled mold, it will be observed thatthefzeores: 7 'andll-are disposed in relation tolthe drag and the cope and in relation to" each other a manne'r to form the castin 'as' shown in plan and elevation in Figs. 1', LS and 19 and as shown in finished' form in Figs. 20 to '32,*inclusive. Thus the core This formed with depressions '7 to accommodate the core 11 fandformthe walls of the'fue'l intake passage with its inlet at one side'ofthe castin}; and itsthree outlets 'at' the'adther s-ide. The core 7' is also formed 'w-ith..two..lolilegi- 'tudinally extending seriies orzrowsof vertical passages or recesses 7 7 fiwhich serve either alone or I in conj unction with adiiacent surfaces ojf the 'd'ra g and the core llgto form 'll-bus Bosses. 2 on the co e serve, to form &

section 15 to form the comparatively thin water jacket walls of the casting, a top section 16 to form the thicker main wall of the cylinder head and the two longitudinal series of interconnecting sections 17 provided by the core passages 7 and forming the through-bolt bosses of the casting. The two series of risers 14 formed in the cope are arranged to registerwith the two series or rows of interconnecting sections 17 of the mold cavity.

As is shown in Fig. 9, the drag-is provided with embedded metal chills 18,18 and 19, 19 which are exposed to the lower ends of some of the interconnecting sections 17 of the mold cavity. A corresponding chill 29 is provided for one of the interconnecting cavity sections, as indicated in Fig; 13. In addition we havejfound it advantageous to provide the drag with metal chills 21, 21

v and 22, 22, as shown in Figs. 3, 15 and 16.

The preferred composition of the baked sand cope has already been stated. While the cope may be formed by any desired procedure, its structure is such as to lend itself readily to rapid and efficient methods of production. We prefer to provide a machine or fixture consisting essentially of a metal base plate with parts attached thereto to form the skim chamber of'the gate and having also a series of low bossesto form the lowerslightly flared ends of the risers 14. Detachable tapered pins or sprues are then readily'set up to form the pouring sprues ofthe gate and the risers of the gate and as the risers 14 are arranged in two rows the sprues forming them can be conveniently attached at their upper ends to two bars so that these. sprues are readily handled in two groups or units.

The cores 7 and 11 may be made of any suitable core sand mixture but we refer a mixture made up of 6 quarts o linseed oil and 24 buckets of Michigan City sand. To give the core 7 a smooth surface, after the usual baking it is preferably painted with'graphite and then dried with a torch. In making the core 11, it is first baked, and then painted with graphite. Next it is pasted to the cope and baked with the latter. The core 11 is thus double baked. When pasting the core 11' to the cope, removable aluminum spacers are introduced between the core and the cope and left during baking and until the cope is ready for use. The accurate relative positioning of the cope and core is thus insured. All of the baked sand parts of the mold, after baking, are rubbed over by the molder in accordance with the usual practice to render them as'smooth as possible.

Before the cope is assembled on the drag the large chills 12 are coated with a liquid paint or mixture composed of;iron oxide and. alcohol, This coating prevents condensation of moisture onthe chills and the resultant formation of vapor in the mold cavity when the hot metal'is' poured.

It will be understood that the cores .7 and 11 are strengthened bythe usual reinforcing wires, not shown, and it will also be understood that the cores are preferably vented by embedding wax rods or wires therein which are melted out when the cores are baked. We prefer also toprovide vent passages around the core extension 7 and the baked sand block 9, as shownin Figs. 6 and 8. V

The drag of the mold is preferably made on a molding machine in accordance with well-known standard practice, the-chills10, 18, 19, 20, 21 and 22 being introduced by assembling them on the pattern when. the drag is formed. a e

In the operation of the mold, the parts having been assembled as shown in the drawings and as above described, the molten metal, such as suitable aluminum alloy, is poured simultaneously through the two pouring gates or sprues 13 The molten metal quickly fills the skim' chambers 13 and rises in the risers 13. From the bottom of the skim chambers the metal is fed gradually and quietly through the relatively restrictedingate passages 13?. into. the adjacent side of the mold cavity at the top thereof. .7

As will be seen from inspection of Fig. 12, the metal first flows down into the bottom of the mold cavity filling the bottom section 15 thereof and thereafter as the pouring continues rises in the cavity to form the jacket sidewall and bolt boss sections and finally the main wall of the cylinder head; and when the cavity has filled the metal rises into the numerous risers 14 which extend upward from the heavy interconnecting sections ofthe mold cavity as previously described. As the molten metal flows into the mold cavity and gradually fills the same the air in the cavity and all vapors and gases which the hot metal drives of from the green sand and the baked sand core and cope parts, find an exceedingly free vent through the numerous risers 14 and also through the porous body of the baked sand cope itself. Consequently the casting produced is substantially entirely free from porosity due to occluded vapors or gases.

In the pouring of the castings, the thin casting sections at the bottom of the mold cavity are naturally the firstto freeze. The freezing of the metal in the bottom parts of the heavier interconnecting sections of the cavity is hastened by thechills 18,19 and 20. The freezing then progresses upward through the mold cavity, the upper parts of the heavy interconnecting sections which form the bolt bosses of the casting being the last to completely freeze and being main;

z inedmeen me n eemmue oe ion with t e s ll mo en metal. ethe heavy .r eelre le- This'ifleltp m te n he risers ntak 11 for t e heeY-y ety e izeti n ehr pke e 111 the heavy bo bos seet oee ofthe est so hat th re ere no. d ew n he e ee io e nd n shr nkage pee-eke here the heavy leter freezin se'etion join the th n ear ie freezing s e ions- Th hills 18, 9 end 2 ojoopere wit the melte mo ie' he ee 14 to secure this result.

en he a ing h s bee pep e t mold is pened and the oopelift :o f-- The trength o he baked. end ope i s ell thet the asting i l ted Wit i from hemel l th p ees and risers ormed 1. t e eeting, by reaso o heir eree forma ion, s r in to e ou e the sting q te etrong y to he bake s nd meee o 'thet the eppe en eet ing can be li d and he l lled a e E it- This s e greet nvenienee n t e se i ur mp ed ld on e mme e el e le es e a es he pelted end. .oop w h th ette hed cas n epd'its eno oeesibek d end c e t be f ed oi? the re n eepd dra an lo ded 0.1 e ewe-k for .treeep rt wey from t e pouring fleo sy here. the gre se ra s. a made p; o e su eble point Wh e the ake 'sendr ler eeen he broken up n ee e te y' hen e n this le te sep a e handlin the etje. end r er .proje'oio s he pa t ng are br ken o f endthe a ge hil .12 reo ye ed While the b ok u ba ed od p rts a e y l o the epel {screening and regonditignjng appgratlis,

I w ll be b erv el t at he 12mm of t larg h ls 2 ie su ht e t e onteeet on of he metel in the ast ng e i freezes end eoo ds to :f oe the eh l iro t sea n the eeet ng end. e neequently t e. ehi l are read ly ,s peret d an no undue .etl'esees ere ple ed. open th ee tipg- Ibi ee metof em mpor eeo in V ew of the bet ehertn ss oheree er etie of each met l e t e luminum :e ey v The lls .2 form the eeoeeee e. in the un e fi ee er th ey ipderheed endfe t Qhile e exoeedi gly emooththe esultin welle oi .ee d .re eseee are e eo fiery smooth flo ne quent y it is only neeo seey ingth ee ipg to subject theple ny etnpr der surface of the cylinder hgpgcl t9 sirn'ple p e tiop ..I. .de "te eeeu ef deei ed smoo h heed we ls for t e combustio e emhepe .ofthe engine 1 Whi e we 'h'e e d s ibed our me d as ha nge-gree-n send drag t .to be undeeet ed that the 21.25% enbe made of; b ke if desired lpelei din eome wh eithe le of venting e ceedingly .d eul it e5? be. to meke 'i he. drag es wel as the "cop lea ed. end-w B i mos eases, Such as that ill stxzeted .fo example, find t poseible .seen e e equete v nti gee eest mge eebetaeltmlly'ieee teem PQI'QQ? with numerous risers. The ygnjiingg mold, cavity during pouring, high i hr n htherieew eene t rou h the'hi' h y pere pody ef the 'beked end. p Whie olee e thetop 'efthe mo d evity, i 9 ex eedie lyi e e d ffective tihetv p ee ieel y 9 geees ere e'el led in t e molte meta n this ee ente We bel e e, f r the u stgn ielf eedom from por sity 'oi't he pest in epe sle ed in our mold. A the eeme. time the rogneee ve ee in o th mete i t e meld eerit beginni g inule hin .see- @9 5 et the bq tempi heeev i ep km e rem e irom'theesup l ee of mo t n me el 5nd extending mduel toward the -puree e 2 .11 molteee pply o. vietes e11 u soun eeee neident .todt'ews nd shri ka o eek bee uee e rys e lize en o th m e 99 1 etee'y point uo oi t ie i lin. u roken eemmepioet o with th molte meta uppl one of the v riou ri e -'l?heimpr ed resul t uscured by mean f our improv d m ld' w l readily be pp eeiet d 'by t ose f looi el? W -1 the predu tio p ligh alloy ca tings Ind ed We be ie e t at We hefi st to. sue ed in t e-eommerei l pro uc n n sub anti S9816" .-,.so.u d an sati fa tory alum num .el oy. -lwe rdeeketecl oylihder; head .eeeti g I rior. .to our d velopment f the Pres nt imprifle form .ofmo d We, as W ;e.S-other.s, 'hed'f und it impos e to pr du e. oee inge o thi he eo r e sonably tr e; f om p si y nd. Sh n ag cre ks and dra i ou det ct e los s th -t ere prohibi -ire- Weter-ie eted cyl nd r h ad eeetingsf mst not l ak When te t d under onei ereble hydraulic pr ssur and enseepep ly e well of h oesti g mus be snbe en ie11y" ee' f om-P ros ty As he's. been pointed ou .theo e pa ts of {the-mo d are p sitioned and 'seeured in d finit-e rela i n to ea h o her to the body o the mo d. by their e gegementwith the hekedeend. pope Qrother baked send pa ts whie themselve eng ge 'the baked and oofp .Thue, "viewf'ef the hardness nd ac ura e em of the. ake "s nd. p rts, 'ec etf mte. po i io ing of he -oore, parts i and, :the-seet one 3 .15 th eestinge pr .ilneed ere-uniformly accurate. :Thi 'e' spe: eiel-ly important where this desirable as in enginesfor motor vehicles, to keep the weight f the-p rteclownato a minimum. Na urally the. .eeSt'ing seetions can -.be. i ideeiig ed hinner uniform aeeuraey is in Zsn'r d than would, b *permieeible ii sueh ac,- enreoy'we e not ;.i.n u.1red o T W ile o or the Sake of elearness we have llustrated"andi-degeiibedindetail a particular 91 1 .nf mold, it; will be nndertbod that one impm emen e iere e'pplicable in various fg'rxns oinaistjng'send ean b ic flil'rigd one in anions WFYSQQtbQI" than thbseesetvforth, the

t bxthe u -oi e hekesl-eend 51F? i he scope of our invention being indicated in the appended claims.

That we claim is:

1. A mold for forming chambered castings of low melting point metal, said mold having a cavity with sections forming the bottom walls of the casting (as it lies in the mold), sections forming the top walls of the casting and interconnecting sections extending upward from the bottom wall sec tions to the top wall sections to form interconnecting parts of the casting, and said mold comprising a drag and a cope which is formed of baked sand and has risers extending upward from the interconnecting sections of the mold cavity.

2. A mold for forming chambered castings of low melting point metal, said mold having a cavity with sections forming the bottom walls of the casting (as it lies in the mold), sections forming the top walls of the casting and interconnecting sections extending upward from the bottom wall sections to the top wall sections to form interconnecting parts of the casting, and said mold comprising a cope having risers extending upward from said interconnecting sections of the mold cavity, the said riser being of sufiiciently large caliber to maintain the metal therein molten until the metal in the mold cavity proper has frozen.

3. A mold for forming chambered castings of low melting point metal, said mold having a cavity with sections forming the bottom walls of the casting (as it lies in the mold), sections forming the top walls of the casting and interconnecting sections extending upward from the bottom wall sections to the top wall sections to form interconnecting parts of the casting, the said bottom walls of the casting being thinner than its top walls and interconnecting parts, and said mold comprising a cope having risers extending upward from the interconnecting sections of the mold cavity.

' 4. A mold for forming chambered castings of low melting point metal, said mold having a cavity with sections forming the bottom walls of the casting (as it lies in the mold), sections forming the top walls of the casting and interconnecting sections extending upward from' the bottom wall sections to'the top wall sections to form interconnecting parts of the casting, and said mold comprising a drag formed of sand with chills embedded therein opposite the said upwardly extending sections of the cavity and a cope formed of baked sand and having risers extending upward from said interconnecting sections of the cavity.

5. A mold for forming chambered castlngs with low melting point metal, said mold having a cavity with sections forming relatively thin bottom walls of the casting (as it lies in the mold), sections forming the top wallsof the casting and interconnecting sections extending upward from the bottom wall sections to the top wall sections to form relatively thick interconnecting parts of the casting, and said mold comprising a drag formed of sand with chills embedded therein opposite the said upwardly extending sections of the cavity and a cope formed of baked sand and having risers extending upward from said interconnecting sections of the cavity.

6. A mold for forming chambered cast-- ings of low melting point metal, said mold having a cavity with sections forming relatively t-hin bottom walls of the casting (as it lies in the mold), sections forming the top walls of the casting and interconnecting sections extending upward fro-1n the bottom wall sections to the topwall sections toform relatively thick interconnecting parts of the casting, and said mold comprising a drag formed of sand with chills embedded therein opposite the said up wardly extending sections ofthe cavity and a cope having risers extending upward from said interconnecting sections of the cavity.

7. In a mold, the combination of a green sand drag-and a cop efforme'd of baked sand and having a pluralityjof upwardly "flared sprue and riser passages so disposed that the flared sprue and riser extensions of the casting formed secure the casting to the cope and enable the casting and the baked sand mass of the cope to be'handled as a unit when the mold is broken up.

8. In a mold for chambered castings, the combination of a green sand drag, a cope formed'of baked sand, and baked sand cores, the said cope having a plurality of upwardly flared sprue and riser passages so disposed that the flared sprue and riser extensions of the casting formed secure the casting to the cope and enable the casting with its contained core sand and the baked sand mass of the cope to be handled as a unit when the mold is broken up.

9. In a-mold, the combination of a body formedin part of green sand and in part of'baked sand, and baked sand core parts, the core parts being positioned in the mold cavity by engagement with the baked sand body structure. 7

10. A mold for forming a cylinder head casting having an inner side that is in part of uniform conformation susceptible of be ing finished by simple machine work and in part of irregular conformation not susceptible of being machine finished, said mold having a composite body structure with sand walls for forming the casting surfaces of uniform conformation and metal walls for forming the casting surfaces of irregular conformation;

11. A mold for forming of low melting point metal a cylinder head casting having and resultant porosity of the casting due to vapor in the mold cavity.

12. In a mold for casting an internal combustion engine cylinder head having a water jacket and a fuel intake passage through the jacket, the combination of a drag having the major part of the mold cavity formed therein, a water jacket core supported in the drag, a baked sand cope, and a fuel passage core attached to the cope.

13. In a mold for casting an internal combustion' engine cylinder head having a ,water jacket and a fuel intake passage through the jacket, the combination of a green sand drag having the major part of the mold cavity formed therein, a water jacketed core supported in the drag, a baked sand cope and a fuel passage core attached to the cope.

14. In a mold for casting an internal combustion engine cylinder head having a water jacket and through-bolt bosses joining the head wall proper and the jacket wall, the combination of a green sand drag in which the major part of the mold cavity is formed with the water jacket side of the cavity down, a baked sand cope forming the top walls of the mold cavity and having riser passages to form upward extensions ofthe said bolt bosses of the casting.

15. In a mold for casting an internal combustion engine. cylinder head having a water jacket and through-bolt bosses joining the head wall proper and the jacket wall, the combination of a green sand drag in which the major part of the mold cavity is formed with the water acket side of the cavity down, said drag having metal chills embedded therein, directly beneath the bolt boss sections of the mold cavity, a baked sand cope forming the top walls of the mold cavity and having riser passages to form upward extensions of the said bolt bosses of the casting.

16. In a mold having a horizontally elongated cavity, a gate to introduce the metal into the cavity comprising an elongated substantially horizontally extending skim chamber of great depth, a sprue leading downward into one end of said chamber, a riser leading upward from the other end of said chamber, and a plurality of ingates of restricted capacity leading from the lower part of the skim chamber into the mold cavity at different points along its length.

In testimony whereof, we hereunto affix our signatures.

CHARLES B. Bonn. DANIEL FROWN. 

